/**
 * Created with IntelliJ IDEA.
 * Description:
 * User:何人亮
 * Date:2024-11-12
 * 22:39
 */
import java.util.Scanner;
class Test{
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        String s=sc.nextLine();
        for(int i=0;i<s.length();i+=2){
            System.out.print(s.charAt(i));
        }
        for(int i=1;i<s.length();i+=2){
            System.out.print(s.charAt(i));
        }
    }
}